Zika hope as vaccines prove 100% effective in tests on mice

Two experimental Zika vaccines have been 100% successful in testing on mice, US researchers have said. The tests could provide a promising sign that similar vaccines under development for humans will protect against the mosquito-borne virus. Researchers tested two different vaccine candidates in a strain of mice that develops Zika symptoms. Mice given either type of vaccine were 100% protected from Zika after a single shot, the study showed, while unvaccinated mice that were exposed to the virus all developed symptoms.

This new mouse model should be useful for comparative assessments of the large range of vaccine candidates now being designed.

Professor Adrian Hill, director of Oxford University’s Jenner Institute

The study, published in the journal Nature, was led by Dr Dan Barouch, of Beth Israel Deaconess Medical Center and Harvard Medical School. Separately, US scientists said they have developed a model of the Zika virus in monkeys. Researchers at the University of Wisconsin said on Tuesday that tests on infected rhesus macaques suggest the monkeys developed antibodies that protected them against a second case of Zika. The World Health Organisation (WHO) declared Zika a global health emergency in February. Several high profile sportspeople have pulled out of the Rio Olympic Games citing concerns about the virus.